RU2638228C2 - Control device for internal combustion engine - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: control device for internal combustion engine comprises a detonation control system, a cooling system and an electronic control unit. The detonation control system is arranged to calculate the value of ignition angle correction according to the presence or absence of detonation in the internal combustion engine so that the amount of ignition angle correction is updated in the direction of increase when detonation occurs and updated in the direction of decrease when no detonation occur. The detonation control system is configured for calculating the ignition angle based on the value of the ignition angle correction and igniting the spark plug of internal combustion engine at the ignition angle obtained by ignition angle delay in response to detonation occurrence. The cooling system is designed for cooling the internal combustion engine. The electronic control unit is arranged to supply a control value corresponding to the target value of the cooling parameter to the cooling system. The cooling system performs cooling of the internal combustion engine according to the control value. The electronic control unit is configured to adjust the control value based on the ignition angle correction value so that when the ignition angle correction value is increased, the correction value for correcting the control value is increased by the correction value in the direction in which the cooling capacity of the cooling system is increased. The cooling system of the internal combustion engine includes a first cooling system which primarily cools the cylinder block of the internal combustion engine, and a second cooling system which primarily cools the inlet periphery. The first cooling system and the second cooling system, respectively, include coolant flow channels independent from each other. The electronic control unit is configured to supply the control value to the second cooling system.

EFFECT: prevention of detonation occurrence by controlling both the ignition angle and temperature of cooling water.

10 cl, 11 dwg

Description

BACKGROUND OF THE INVENTION

1. The technical field to which the invention relates.

[0001] The invention relates to a control device for an internal combustion engine and, in particular, relates to a control device suitable for controlling an internal combustion engine mounted on a vehicle.

2. Description of the Related Art

[0002] In the publication of Japanese patent application No. 2001-304028 (JP 2001-304028 A) discloses an internal combustion engine having both a function of delaying the ignition angle according to the detonation intensity and a function of decreasing the target temperature of the cooling water according to the detonation intensity. It is known that in an internal combustion engine, with an increase in the delay of the ignition angle, detonation is more difficult to occur, while the fuel consumption indicator is deteriorating. It is also known that when the temperature of the cooling water decreases, the temperature in the cylinder decreases, while knocking is more difficult to occur.

[0003] When knocking occurs in the aforementioned conventional internal combustion engine, a condition in which knocking is difficult to occur is created by both a delay in the ignition angle and a decrease in the temperature of the cooling water. In this case, compared with the case where detonation is only prevented by delaying the ignition angle, it is possible to reduce the ignition angle delay amount necessary to prevent detonation. Therefore, in accordance with the aforementioned conventional internal combustion engine, the occurrence of detonation can be appropriately prevented without excessive delay in the ignition angle, and, accordingly, without a significant deterioration in fuel consumption.

SUMMARY OF THE INVENTION

[0004] In an internal combustion engine, the ignition angle can be immediately changed by changing the control angle. Therefore, if the ignition angle is set with a delay according to the detonation intensity, the operating parameters of the internal combustion engine immediately change to a state suitable for eliminating detonation, in accordance with the ignition angle.

[0005] On the other hand, the temperature of the cooling water reaches the target value with some delay after changing such a target value. Therefore, in the case when the target value of the temperature of the cooling water decreases according to the intensity of the detonation, some time is required for the operating parameters of the internal combustion engine to reach a state suitable for eliminating detonation in accordance with the temperature of the cooling water.

[0006] In this regard, there are still reserves for improving the aforementioned conventional internal combustion engine with respect to the requirement of implementing operational parameters that are optimal for eliminating detonation, both by the ignition angle and by the temperature of the cooling water.

[0007] As an invention, there is provided a control device for an internal combustion engine that can effectively prevent detonation by appropriately controlling both the ignition angle and the temperature of the cooling water.

[0008] A control device for an internal combustion engine according to a first aspect of the invention includes a knock control system, a cooling system, and an electronic control unit. The detonation control system is configured to calculate the found value of the ACS according to the presence or absence of detonation of the internal combustion engine so that the found value of the ACS is updated in the increasing direction when knocking occurs and is updated in the decreasing direction when knocking does not occur. The detonation control system is configured to calculate the ignition angle based on the found value of the COD. The knock control system is configured to ignite the spark plug of the internal combustion engine at an ignition angle obtained by delaying the ignition angle in response to the occurrence of detonation. The cooling system is designed to cool the internal combustion engine. The electronic control unit is configured to supply a control value corresponding to the target value of the cooling parameter to the cooling system so that the cooling system cools the internal combustion engine in accordance with the control value. The electronic control unit is configured to adjust the control value based on the found value of the ACS so that if the found value of the ACS increases, the correction amount for correcting the control value increases in magnitude of the correction in the direction in which the cooling capacity of the cooling system increases.

[0009] According to the control device for the internal combustion engine in accordance with this object, the ignition angle is calculated based on the found value of the ACS and, in addition, is delayed in response to the occurrence of detonation. Therefore, after the occurrence of detonation, the internal combustion engine immediately changes to a state suitable for preventing detonation using the ignition angle. In addition, the control value for the cooling system is adjusted based on the found value of the ACS. Since the found COD value is updated according to the presence or absence of detonation, it reflects the tendency for detonation to occur. Therefore, by adjusting the control value of the cooling capacity of the cooling system according to the found value of the ACS, the control value can be made suitable to prevent detonation before detonation occurs, and, moreover, it can be made to track the tendency for detonation to occur. Therefore, the occurrence of detonation can be effectively prevented using both the ignition angle and the operating temperature parameters.

[0010] In the control device for the internal combustion engine according to the aforementioned object, the electronic control unit may be configured so as not to adjust the control value when the number of updates of the found value of the ACS according to the presence or absence of detonation is less than a predetermined value, and may be configured so that adjust the control value when the number of such updates is a predetermined value or more.

[0011] According to the control device for the internal combustion engine in accordance with this object, the correction of the control value for the cooling system can only be performed in a state where the update of the found value of the ACS is performed sufficiently. When the update is repeated, the found COD value becomes the value corresponding to the tendency of detonation. Therefore, it can be effectively prevented that improper correction is carried out at the stage when the tendency for detonation to occur does not adequately reflect the found value of the COD.

[0012] In the control device for the internal combustion engine according to the aforementioned object, the electronic control unit may be configured to update the found value of the cooling parameter based on the found value of the ACS so that when the found value of the ACS increases, the update amount to update the found value of the cooling parameter increases in magnitude of renewal in the direction in which the cooling capacity of the cooling system increases. The electronic control unit may be configured to determine a target value based on a base value of a cooling parameter and a found value of a cooling parameter.

[0013] According to the control device for the internal combustion engine in accordance with this object, the target value of the cooling parameter is determined based on the base value of the cooling parameter and the found value of the cooling parameter. In addition, when the found value of the ACS increases, the found value of the cooling parameter is substantially updated in the direction in which the cooling capacity increases. Therefore, when it can be determined that the occurrence of detonation is more likely with a higher found value of the ACS, the temperature state of the internal combustion engine can substantially approach the state suitable for preventing detonation by significantly increasing the cooling capacity.

[0014] In the control device for the internal combustion engine according to the aforementioned object, the electronic control unit may be configured to calculate an update amount of a found value of a cooling parameter based on a found value of the ACS and update the found value of a cooling parameter with an update amount so that when found the value of the ACS increases, the amount of update increases in magnitude of the update in the direction in which the cooling capacity of the cooling system denia increases.

[0015] According to the control device for the internal combustion engine in accordance with this object, the found value of the cooling parameter is updated using the update value calculated based on the found value of the ACS. Since, when the found value of the ACS increases, the update amount is substantially updated in the direction in which the cooling capacity increases, the found value of the cooling parameter can be properly updated based on the found value of the ACS.

[0016] In the control device for the internal combustion engine according to the aforementioned object, the detonation control system may be configured to calculate the determined SAC value for each of the plurality of working areas of the internal combustion engine. The electronic control unit can be configured to store the update rule for each of the work areas, in order to update the found value of the cooling parameter for each of the work areas based on the found value of the ACS for each of the work areas. The electronic control unit can be configured to update the found value of the cooling parameter in each individual work area according to the update rule for each of the work areas.

[0017] According to the control device for the internal combustion engine in accordance with this object, the found value of the cooling parameter in each individual work area is updated according to the found value of the ACS calculated for each work area and the update rule stored for each work area. Therefore, the target value of the cooling parameter is also calculated for each work area. The tendency for knocking to occur may vary depending on the work areas. By using the target value calculated for each work area, the cooling system can be properly brought into a state corresponding to the tendency for detonation to occur in each individual work area.

[0018] In a control device for an internal combustion engine according to the aforementioned object, the cooling parameter may be a temperature of the cooling medium. The electronic control unit can be configured to supply the target temperature of the cooling medium to the cooling system as a control value so that when the found value of the ACS increases, the correction value of the target value of the temperature of the cooling medium increases in the direction of low temperature. The cooling system may be configured to control the cooling medium of the cooling system so as to realize the target temperature of the cooling medium.

[0019] According to the control device for the internal combustion engine in accordance with this object, the target value of the temperature of the cooling medium is supplied as a control value to the cooling system. In the cooling system, the cooling medium is controlled in order to realize the target value. When the found value of the SAS increases, the target value is substantially adjusted in the direction of low temperature. Therefore, when the occurrence of detonation becomes more likely, the temperature operating parameters of the internal combustion engine can be biased in a direction suitable for preventing detonation.

[0020] In a control device for an internal combustion engine according to the aforementioned object, the cooling system may include an electric water pump capable of varying the discharge flow rate of the cooling medium. The cooling parameter may be the discharge flow rate of the electric water pump. The electronic control unit can be configured to supply the target value of the discharge flow rate to the cooling system as a control value so that when the found value of the ACS increases, the correction value of the target value of the discharge flow increases in the direction of increasing value.

[0021] According to the control device for the internal combustion engine in accordance with this object, the target value of the injected flow rate of the cooling medium is supplied as a control value to the cooling system. In the cooling system, an electric water pump is controlled in order to realize the target value. When the found value of the COURT increases, the target value is substantially adjusted in the direction of increasing value. When the target discharge rate increases, the cooling capacity of the cooling system increases. Therefore, when the occurrence of detonation becomes more likely, the temperature operating parameters of the internal combustion engine can be biased in a direction suitable for preventing detonation.

[0022] In the control device for the internal combustion engine according to the aforementioned object, the internal combustion engine may include a first cooling system that mainly cools the cylinder block of the internal combustion engine, and a second cooling system that mainly cools the periphery of the inlet compared to first cooling system. The first cooling system and the second cooling system, respectively, may include channels of flows of the cooling medium, independent of each other. The electronic control unit may be configured to provide a control value to the second cooling system.

[0023] According to a control device for an internal combustion engine in accordance with this aspect, the internal combustion engine is cooled by a first cooling system, which mainly cools the cylinder block, and a second cooling system, which mainly cools the periphery of the inlet compared to the first cooling system. The second cooling system is separated from the first cooling system and, in response to a control value from the electronic control unit, exhibits greater cooling ability when the occurrence of detonation becomes more likely. To prevent detonation, it is effective to reduce the temperature of the periphery of the inlet. On the other hand, a decrease in the temperature of the cylinder block leads to an increase in mechanical friction and cooling losses, and thus leads to a decrease in fuel consumption. In accordance with this aspect, it is possible to properly cool only the periphery of the inlet according to the tendency for detonation to occur without substantially reducing the temperature of the cylinder block. Therefore, the occurrence of detonation can be appropriately prevented without impairing fuel consumption.

[0024] In a control device for an internal combustion engine according to the above object, the electronic control unit may be configured to supply a target temperature to the first cooling system. The first cooling system may be configured to control the cooling medium of the first cooling system in order to realize the target temperature of the first cooling system. The electronic control unit may be configured to reduce the target temperature of the first cooling system when the second cooling system has reached the cooling limit.

[0025] According to a control device for an internal combustion engine in accordance with this object, when entering a state where the temperature operating parameters of the internal combustion engine cannot be displaced in a direction more suitable for preventing detonation by the second cooling system, the target temperature of the first system cooling may be reduced. When the temperature of the first cooling system decreases, the temperature operating parameters of the internal combustion engine are shifted in a direction preferred to prevent detonation. Therefore, operating conditions that can prevent detonation can be further expanded.

[0026] In the control device for the internal combustion engine according to the aforementioned object, the electronic control unit may be configured to permit a decrease in the target temperature of the first cooling system only when the temperature of the cooling medium of the first cooling system is higher than a certain temperature.

[0027] According to the control device for the internal combustion engine in accordance with this object, it is possible to prevent the temperature of the cooling medium of the first cooling system from being reduced to a certain temperature or less. When the temperature of the first cooling system decreases excessively, the fuel consumption of the internal combustion engine deteriorates significantly. By keeping the temperature of the first cooling system at a temperature not lower than a certain temperature, operating conditions that can prevent detonation can be largely ensured.

[0028] In the control device for the internal combustion engine according to the aforementioned object, the electronic control unit may be configured to reduce the target temperature of the first cooling system based on the found value of the ACS.

[0029] According to the control device for the internal combustion engine in accordance with this object, the target temperature of the first cooling system can be reduced in accordance with the tendency for detonation to occur. Therefore, both the first cooling system and the second cooling system can be controlled appropriately at temperatures suitable to prevent detonation.

Brief Description of the Drawings

[0030] The features, advantages, as well as the technical and industrial relevance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like elements are used with like numerals and in which:

FIG. 1 is a diagram showing a configuration of a first embodiment of the invention.

FIG. 2 is a timing chart for explaining the operation of the knock control system in the first embodiment of the invention.

FIG. 3 is a diagram for explaining a map of base water temperatures of an NT system of a first embodiment of the invention.

FIG. 4 is a block diagram of a program executed by an ECU in a first embodiment of the invention.

FIG. 5 is a timing chart showing an example of the operation of the first embodiment of the invention.

FIG. 6 is a diagram for explaining a state in which a found SAC value is calculated for each of a plurality of divided work areas in a second embodiment of the invention.

FIG. 7 is a block diagram of a program executed by an ECU in a second embodiment of the invention.

FIG. 8 is a block diagram of a program executed by an ECU in a third embodiment of the invention.

FIG. 9 is a diagram for explaining an area in which a correction is applied to a target temperature of a BT system in a fourth embodiment of the invention.

FIG. 10 is a block diagram of a program executed by an ECU in a fourth embodiment of the invention.

FIG. 11 is a timing chart showing an example of operation of a fourth embodiment of the invention.

Detailed Description of Embodiments

[0031] FIG. 1 is a diagram showing a configuration of a first embodiment of the invention. As shown in FIG. 1, the system of this embodiment includes an internal combustion engine 10. The internal combustion engine 10 is an engine that is used when mounted on a vehicle and includes a cylinder block 12 and a cylinder head 14. In the cylinder block 12 and the cylinder head 14, respectively, cooling water channels independent of each other are formed.

[0032] The cooling water channel of the cylinder block 12 is part of a BT (high temperature) system 16 configured to cool mainly the cylinder block 12. The BT system 16 includes a water pump (B / H) 18 on the inlet side of the cylinder block 12. The B / H 18 is mechanically driven by the internal combustion engine 10, so as to be able to supply cooling water to the BT system 16 to the cylinder block 12.

[0033] A 20 W water temperature sensor is located on the output side of the cylinder block 12. The 20 W water temperature sensor produces an ethwH signal corresponding to the temperature of the cooling water flowing in the W system 16.

[0034] The BT system 16 includes a circulation channel 24 equipped with a BT radiator 22, and a bypass channel 26 bypassing the BT radiator 22. The BT radiator 22 can cool the cooling water flowing therethrough by air flow when the vehicle is moving. The BT radiator 22 is equipped with a cooling fan (not shown) and, if necessary, can cool the cooling water also with the air supplied by the cooling fan.

[0035] The bypass channel 26 has one end connected to the circulation channel 24 through a thermostat (T / C) 28. The T / C 28 is a three-way valve configured to change the flow area according to the temperature of the cooling water. More specifically, when the temperature of the cooling water is low, T / C 28 works to close the channel leading from the BT radiator 22 to B / H 18, forcing cooling water to circulate exclusively through the bypass channel 26, and when the temperature of the cooling water rises, T / C 28 It works to increase the proportion of cooling water that flows through the VT radiator 22.

[0036] On the other hand, the cooling water channel of the cylinder head 14 is part of the NT (low temperature) system 30. Compared to the BT system 16, the HT system 30 is a cooling system designed to cool mainly the periphery of the inlet openings. The HT system 30 includes an electric water pump (E-B / H) 32 on the inlet side of the cylinder head 14. E-V / N 32 operates in an operating mode corresponding to a mode signal supplied externally so as to be able to supply cooling water to the cylinder head 14 with a pump capacity corresponding to the mode signal.

[0037] The HT temperature sensor 34 is located on the output side of the cylinder head 14. The sensor 34 NT water temperature generates a signal ethwL corresponding to the temperature of the cooling water flowing in the NT system 30.

[0038] The HT system 30 includes a circulation channel 38 equipped with an HT radiator 36 and a bypass channel 40 bypassing the HT radiator 36. Like the HT radiator 22, the HT radiator 36 can cool cooling water by air flow when the vehicle is moving or with using cooling air generated by the integrated cooling fan (not shown).

[0039] The bypass channel 40 has one end connected to the circulation channel 38 via a three-way valve 42. In response to an opening signal from the outside, the three-way valve 42 can change the ratio between cooling water that flows through the bypass channel 40 and cooling water that flows through the NT radiator 36.

[0040] The system shown in FIG. 1 includes an electronic control unit (ECU) 44. ECU 44 can determine the temperature of the cooling water of the VT system 16 (hereinafter referred to as “VT water temperature”) and the temperature of the cooling water of the NT system 30 (hereinafter referred to as “NT water temperature”) based on the signal ethwH sensor 20 W water temperature and ethwL signal sensor 34 NT water temperature. In addition, the ECU 44 can control the states of the cooling fan BT of the radiator 22 and the cooling fan NT of the radiator 36. In addition, the ECU 44 can also control the states of the EB / H 32 and the three-way valve 42 NT of the system 30.

[0041] The ECU 44 is also electrically connected to various sensors and actuators located in the internal combustion engine 10. For example, the ECU 44 may set the ignition timing for each of the spark plugs 46 attached to the respective cylinders of the internal combustion engine 10. In addition, the ECU 44 may determine the in-cylinder pressure of each cylinder based on the output of the cylinder pressure sensor 48 (DDC) provided for each cylinder. In addition, the ECU 44 may determine engine revolutions (NE) based on the output of the RPM sensor 50 and may determine the degree of accelerator opening (Ass) based on the output of the accelerator opening degree sensor 52.

[0042] The system of this embodiment is equipped with a knock control system (COD). FIG. 2 is a diagram for explaining the operation of the COURT. In FIG. 2, the ordinate axis indicates the ignition angle (the downward direction is the delay direction) of a particular cylinder of the internal combustion engine 10, while the abscissa axis indicates the time period.

[0043] In the internal combustion engine 10, when the ignition angle continues to be leading, knocking quickly occurs. Further, the ignition angle at which detonation occurs in the lead process will be referred to as the “knock threshold point (AP point)”. In the internal combustion engine 10, until detonation occurs, fuel consumption characteristics are improved when the ignition angle is more advanced. Therefore, it is preferable that the ignition angle of each cylinder is maintained near the PD point in such a way as to prevent detonation.

[0044] The ignition angle indicated by 54 in FIG. 2 is a reference value 54 of the ignition angle, which is set according to the operating conditions of the internal combustion engine 10. The base value 54 is the ignition angle set ahead of the standard point of the PD.

[0045] The arrow indicated by 56 in FIG. 2, denotes the found value of the COURT. The found value 56 of the ACS, which further means the value of the correction of the ignition angle, is updated in the direction of increase (e.g., by α) in response to the occurrence of detonation, while the found value 56 of the ACS is updated in the direction of decrease (e.g., by α) in the state when detonation does not occur. Therefore, the found value of the ACS becomes a large value at operating parameters, when detonation tends to occur, and the found value of the ACS becomes a small value at operating parameters, when detonation is difficult to occur.

[0046] The system of this embodiment performs feedback control of the ignition angle so that the PD point is monitored using, as the central value, the value obtained by adding the found CRS value 56 to the base value 54. More specifically, in addition to the base value 54 and the found value of the COURT 56, the ECU 44 calculates the value of the feedback correction for the ignition angle. This feedback correction value is substantially updated in the direction of delay (e.g., by β) in response to the occurrence of detonation, and is updated in the advance direction (e.g., by γ, substantially less than β) when detonation does not occur. Each of the values β and γ of the update of the feedback correction value is significantly larger than the value of a update of the found value of the COURT.

[0047] The waveform indicated by 58 in FIG. 2 denotes the final ignition angle obtained by adding a feedback correction value. The ECU 44 requires ignition at a final ignition angle 68 for the spark plug 46. With this configuration, in the internal combustion engine 10, it is possible to achieve an ignition angle that is optimal for both detonation and fuel consumption.

[0048] As described above, the internal combustion engine 10 of this embodiment includes a BT system 16 configured to cool mainly the cylinder block 12. The BT system 16 causes cooling water to circulate through the bypass channel 26 when the BT has a low water temperature, such as, for example, immediately after starting the internal combustion engine 10. In this case, since the amount of heat generated is small, the water temperature increases rapidly. The temperature of the cylinder block 12 significantly affects the mechanical friction and losses during cooling of the internal combustion engine 10. If it is possible to raise the water temperature in advance, then the adverse effects caused by these factors can be reduced at an early stage, and thus, it is possible to increase the fuel consumption characteristics immediately after starting the engine.

[0049] Since the internal combustion engine 10 is heated in such a way that when the water temperature reaches the set temperature (for example, from 85 ° C to 90 ° C) of the thermostat 28, the bypass channel 26 closes, while the cooling water begins to circulate through VT radiator 22. When cooling water begins to flow through the VT radiator 22, the amount of heat generated increases to prevent the increase in VT temperature of the water. Therefore, the VT temperature control of the water is carried out near the set temperature by the operation of T / C 28.

[0050] The ECU 44 may determine the WT temperature of the water based on the ethwH signal of the 20 W water temperature sensor. When the BT water temperature is higher than the set temperature T / C 28 or when the BT water temperature needs to be lower than the set temperature T / C 28, the ECU 44 issues a drive command to the VT radiator fan 22. The cooling capacity of the VT radiator 22 increases with the operation of the fan. Therefore, according to this embodiment, the BT water temperature can be controlled so as to maintain it at the target water temperature equal to or close to the set temperature T / C 28. Next, the target water temperature for controlling the BT will be referred to as “BT target water temperature”.

[0051] The internal combustion engine 10 includes an NT system 30 configured to circulate cooling water through the inside of the cylinder head 14. According to the NT system 30, the periphery of the inlet openings can be effectively cooled without significantly reducing the temperature of the cylinder block 12. As described above, the temperature of the cylinder block 12 significantly affects the loss of the internal combustion engine 10. On the other hand, the temperature near the inlet openings significantly affects the temperature of the intake air and, thus, significantly affects the conditions for the occurrence of detonation. Therefore, according to the NT system 30, it is possible to create temperature operating parameters suitable for preventing detonation without increasing losses due to mechanical friction, etc.

[0052] In this embodiment, by changing the state of the three-way valve 42, the NT system 30 can change the ratio between the amount of cooling water that flows through the bypass channel 40 and the amount of cooling water that flows through the NT radiator 36. In addition, by changing the operating mode provided by the mode signal supplied to the E-B / H 32, you can change the amount of cooling water that circulates in the NT system 30. In addition, you can change the heat-generating ability by controlling the operation of the fan, built-in about in the NT radiator 36. By performing feedback control of these components based on the ethwL signal of the sensor 34 NT water temperature, ECU 44 can control the NT water temperature at an arbitrary target water temperature (hereinafter referred to as "NT target water temperature"), which is independent from BT target water temperature.

[0053] FIG. 3 shows a NT map of the base values stored in ECU 44 for determining the NT of the target water temperature. On the map shown in FIG. 3, each of the NT base values is determined based on the relationship between the engine speed NE and the engine load KL. The ECU 44 determines the NT target water temperature based on the NT base value, updated from the map. The ECU 44 calculates the engine load KL (more specifically, the load efficiency) based on the Ace degree of accelerator opening in a known manner.

[0054] The tendency for knocking to occur varies with engine operating conditions. For example, a low-speed region with a high load is an area where detonation tends to occur. The map shown in FIG. 3 is determined in such a way that the NT base value decreases in the region where the occurrence of detonation is more likely. As a result, the target water temperature is set at a low temperature in an area where there is a tendency to manifest detonation.

[0055] When NT decreases the target water temperature, NT the water temperature decreases so that detonation is more difficult to occur. That is, in a work area that seeks to cause knocking, the internal combustion engine 10 of this embodiment creates temperature operating parameters that make knocking difficult. Therefore, in the internal combustion engine 10 of this embodiment, the occurrence of detonation can be effectively prevented throughout the entire working area without relying on a large delay in the ignition angle.

[0056] As described above, the internal combustion engine 10 of this embodiment is configured to prevent the occurrence of detonation by controlling the ignition angle with the aid of the ACS. In addition, the internal combustion engine 10 is configured to reflect the working area of the internal combustion engine 10, i.e. engine speed NE and engine load KL, at NT target water temperature, thereby preventing the occurrence of detonation also according to the aspect of the temperature operating parameters.

[0057] If an attempt is made to prevent the occurrence of detonation with support only the operation of the ACS, then a large delay in the ignition angle is required in the work area, where there is a tendency to manifest detonation, respectively, the fuel consumption characteristics of the internal combustion engine 10 tend to deteriorate. On the contrary, if the temperature operating parameters regarding detonation are improved in such an operating region, the ignition angle delay amount can be reduced in order to avoid deterioration of fuel consumption. In this regard, setting the NT to the target water temperature using the map shown in FIG. 3, is effective for improving fuel consumption.

[0058] However, the tendency for knocking to occur is not determined uniformly for the working area of the internal combustion engine 10. Therefore, if the NT water target temperature is set taking into account only the working area, there is a possibility of a situation where the tendency for the detonation to occur is not eliminated sufficiently, and, accordingly, the occurrence of an excessive delay value cannot be prevented.

[0059] The situation described above can be avoided, for example, by reflecting the state of occurrence of detonation at NT target water temperature. That is, by decreasing the NT target water temperature in a state where knocking often occurs, and increasing the NT target water temperature in a state where knocking does not occur, an excess delay can be prevented.

[0060] As a method for reflecting the state of occurrence of detonation at a target water temperature, for example, the following methods are considered.

1. A uniform decrease in NT target water temperature during the occurrence of detonation.

2. The decrease in NT target water temperature by a width corresponding to the intensity of detonation during the occurrence of detonation.

[0061] According to method 1 or 2, when detonation still occurs in a state where the ignition angle is controlled by the ECM, the temperature operating parameters of the internal combustion engine 10 can be changed in the direction in which detonation is difficult to occur by decreasing the temperature of the NT system 30. In addition , according to method 2, the temperature operating parameters can be significantly changed during the intensification of detonation. According to these methods, since the tendency for knocking to occur can affect the target water temperature, a certain effect can be obtained to prevent an excessive ignition delay.

[0062] However, the temperature operating parameters of the internal combustion engine 10 do not change at all when only NT changes in the target water temperature. That is, for the temperature operating parameters to change, it is necessary that the NT water temperature reaches the NT target water temperature after the change. Therefore, in fact, the sequence of the following phenomena tends to occur according to method 1 or 2.

[0063] (1) Knocking occurs. (2) The ignition angle is delayed during the operation of the COURT. At the same time, NT target water temperature decreases. (3) Since the temperature operating parameters do not change immediately, detonation occurs again. (4) The ignition angle is delayed again. NT target water temperature also decreases again. As a result, a large delay is set, and additionally NT, the target water temperature decreases to a value that is too low. (5) Since the ignition angle is significantly delayed, the detonation is eliminated. Since the delay is large, this condition is unfavorable in terms of fuel consumption. (6) Since the NT temperature of the water approaches too low the target temperature of the water, the ignition angle becomes excessively large with respect to the point of PD. (7) After that, the ignition angle moves to a state in which the ignition angle tracks the AP point. In this case, the target water temperature is adjusted to a temperature that is too high.

[0064] Thus, according to method 1 or 2, redundant changes similar to rolling occur both with the ignition angle and with the NT target water temperature due to the delay time required for the NT water temperature to reach the NT target temperature water. As a result, the following disadvantages arise in the internal combustion engine 10.

- Temporary deterioration in fuel consumption due to excess delay.

- Excessive cooling of the internal combustion engine 10 due to too low NT target water temperature. Deterioration in fuel economy with such excessive cooling.

[0065] As described above, the internal combustion engine 10 of this embodiment updates the found SAC value based on the detonation occurrence state. At the stage when the update is sufficiently repeated, the found value of the COURT becomes a value that correctly indicates the trend of detonation. For example, even at the moment when the occurrence of detonation is not established, if the found value of the ACS is a large value, it can be determined that the internal combustion engine 10 is in a state where there is a tendency for the occurrence of detonation. On the other hand, even at the moment when the occurrence of detonation is established, if the found COV value is a value that is not so large, it can be determined that the internal combustion engine 10 is in a state where the tendency for the occurrence of detonation is not so noticeable.

[0066] The tendency for knocking to occur gradually changes in the internal combustion engine 10, and does not change significantly before and after detonation. Similarly, the found value of the COURT is gradually updated according to the state of occurrence of detonation. Therefore, if the found VAS value is reflected in the NT at the target water temperature, then the NT target water temperature continues to be adjusted by a small value according to the state of detonation occurrence and continues to stably correspond to the trend (detonation occurrence. If the NT change width of the target water temperature is so small, the actual NT water temperature is not significant deviates from the NT target water temperature.Therefore, if the found value of the VAS is reflected in the NT target water temperature, the temperature working parameters If the temperature operating parameters of the internal combustion engine 10 can continue to correspond to the trend of detonation, then there will be neither a decrease in fuel consumption due to excessive cooling, nor a decrease in fuel consumption due to excessive angle of ignition delay. Therefore, in this embodiment, NT, the target water temperature is set based not only on the working area of the engine 10 ennego combustion, but the found value OVC.

[0067] FIG. 4 is a block diagram of a program executed by the ECU 44 in this embodiment to implement the function described above. In this embodiment, the ECU 44 stores a computer program for executing the procedure shown in FIG. 4 and includes hardware, for example, an interface, a storage device, and a CPU (central processing unit) to provide such an implementation.

[0068] The program shown in FIG. 4, runs at a predetermined time of about 3 seconds. This predetermined time is the time taken in consideration of the delay necessary for the NT water temperature to follow the change after the NT changes the target water temperature. When executing the program, it is first determined whether the NT system 30, the VT system 16, and the ACS are operating normally (step 100). The system of this embodiment is equipped with fault detection functions, respectively, for the NT system 30, the VT system 16, and also the ACS. More specifically, at step 100, it is determined whether a fault condition is absent in any of these systems.

[0069] When a failure is detected in any of the NT systems 30, BT systems 16, and the ACS, the current program immediately ends. On the other hand, if it is determined that all systems are operating normally, then it is determined whether or not the water temperature is higher than (a) ° C (step 102). In the internal combustion engine 10, detonation occurs when the inside of the cylinder gains heat. Therefore, detonation does not occur until the internal combustion engine 10 is warmed to a certain degree, (a) ° C is the temperature to determine whether or not the heating has reached a certain level, and is set in the region from 40 ° C to 50 ° C. Therefore, if the confirmation that the VT water temperature> (a) is denied at this stage, it can be determined that this is not the state when detonation occurs, so there is no need to cool the periphery of the inlets using the NT system 30. In this case, the computer 44 ends the current program immediately.

[0070] On the other hand, if it is determined at step 102 that the condition is established: VT water temperature> (a), then it is determined whether or not the operating parameters are established at which the found value of the ECM can affect the control of the internal combustion engine 10 (step 104). More specifically, it is determined whether or not all of the following conditions have been established. If any of the following conditions is not established:

- lower range limit NE <engine speed NE <upper range limit NE

- lower limit of the range KL <load KL of the engine <upper limit of the range KL

- lower limit of the range NT <NT water temperature <NT upper limit of the range NT

- lower limit of the temperature range of the outdoor air <temperature of the outdoor air <upper limit of the temperature range of the outdoor air

- no malfunction of other paired devices

- the absence of a request from other modules to prohibit updating the ACS then it is determined that this is not the state where the found value of the ACS can affect the control of the internal combustion engine 10. In this case, the current program closes immediately.

[0071] If it is determined that all the conditions described above have been established and, accordingly, operating parameters have been established that are able to use the found value of the ACS, then it is determined whether or not the number of updates of the found value of the ACS has reached the set value (step 106). This "setpoint", which is a value of 1 or more, is experimentally determined in advance as a determining value for determining whether or not the found value of the COURT has become a value that correctly reflects the tendency for detonation to occur. If this definition is negative, it can be determined that it is still too early to reflect the found value of the SAS at the NT target water temperature. In this case, the current program ends immediately.

[0072] On the other hand, if the determination at step 106 is affirmative, processes are carried out to reflect the found value of the ACS at the NT target water temperature. More specifically, first, the NT update amount is calculated based on the found SAC value (step 108). ECU 44 stores the card shown in step 108 of FIG. 4. On this map, the relationship between the found values of the COURT and NT update values is determined. According to the process at this stage, when the found value of the COURT increases, the NT update value is set to a larger value.

[0073] After the process described above is completed, the NT found value is updated according to the following formula (step 110).

(NT found value) = (last value) + (current update value) ... (formula 1), in which

The “last value” is the NT found value calculated in the last program, and the “current update value” is the NT update value calculated in step 108 in the current program. According to the process described above, when the found value of the COURT increases, the NT found value is substantially updated in the direction of increase.

[0074] After the NT update of the found value is completed, then, using the updated NT of the found value, the NT water target temperature is set according to the following formula (step 112).

(NT target water temperature) = (NT base value) - (NT found value) ... (formula 2).

As described above, NT found value is significantly updated in the direction of increase, when the found value of the COURT increases. Therefore, the NT target water temperature tends to update to a lower temperature relative to the NT base value in a state where the occurrence of detonation is more likely.

[0075] The ECU 44 controls the EV-H 32, the three-way valve 42, and the NT fan of the radiator 36 so that the NT water temperature reaches the NT target water temperature. Therefore, according to the processes described above, the NT temperature of the water becomes lower temperature in a state where the occurrence of detonation is more likely, while the temperature operating parameters of the internal combustion engine 10 change in the direction in which detonation is difficult to occur.

[0076] FIG. 5 is a timing chart for explaining an example of the operation of the internal combustion engine 10, which is implemented by periodically executing the program described above. The triangular waveform shown in the uppermost row of FIG. 5, each represents the occurrence of detonation and its intensity.

[0077] In the example shown in FIG. 5, detonation with high intensity occurs at time t1. In response to it, the ignition angle is substantially delayed from the base value 54 and then gradually rotates in the advance direction. Ahead of the ignition angle, detonation with a lower intensity occurs at time t2. In response to this occurrence, the ignition angle is delayed again in a stepwise manner. From time t2 to time t3, significant detonation does not occur, and the ignition angle tracks the AP point. In this case, the found value of the COURT 56 is set so as to correspond to the difference between the base value 54 and the final angle 58 of the ignition.

[0078] In the example shown in FIG. 5, detonation occurs again at time t3. In response to it, the ignition angle changes again in the delay direction in a stepwise manner. In response to the state when there is a tendency to manifest detonation, the found value of the COURT is updated in the direction of increase. At time t4, the detonation occurs again, and the ignition angle and the found value of the ECM are further updated. As a result, at time t5, the number of updates of the found value of the ACS reaches the set value (see position 60), and NT the target water temperature is adjusted in the direction of low temperature based on the found value of the ACS.

[0079] At time t6, in response to a new occurrence of detonation, the found SAC value is further updated in the direction of increase. In addition, based on the increased found value of the SAS, NT, the target water temperature is further adjusted in the direction of low temperature. After time t7, since there is no constant occurrence of detonation, the ignition angle moves in the leading direction to the base value 54, and the found value of the CRM is gradually updated to a lower value. As a result of NT, the target water temperature rises to the normal set temperature after time t7.

[0080] As described above, the internal combustion engine 10 of this embodiment can effectively prevent the occurrence of detonation by delaying the ignition angle and changing the temperature operating parameters by the NT system 30. By updating the NT target water temperature based on the found value of the ECM, the temperature operating parameters of the engine 10 internal combustion engines can be appropriately changed without excessive reaction to the occurrence of individual detonations, so as to correctly eliminate the tendency to iknoveniya detonation. Therefore, according to this embodiment, the occurrence of detonation can be effectively prevented without excessive delay in the ignition angle.

[0081] In this embodiment, NT correction of the target water temperature is allowed only when the update of the found COUR value has been repeated sufficiently. Through sufficient updates, the found value of the COURT becomes a value that properly indicates the tendency for detonation to occur. Therefore, according to this embodiment, it is possible to prevent the NT from target water temperature being improperly updated at the stage when the tendency for the detonation to occur does not correctly reflect the found value of the COD.

[0082] Furthermore, in this embodiment, the NT target water temperature is updated at a predetermined time of about 3 seconds. During the 3-second refresh period, the NT water temperature follows to some extent the NT target water temperature after the update, and the found value of the SAS also follows to some extent the operating parameters. Therefore, according to this embodiment, it is possible to effectively prevent an excessive increase or decrease in NT of the target water temperature.

[0083] In the first embodiment described above, it is assumed that the internal combustion engine 10 includes a BT system 16 and an HT system 30, however, the application of the invention is not limited to this. That is, the invention made to set the target temperature of the cooling water based on the found value of the ACS can also be applied to a conventional internal combustion engine including a single channel of cooling water.

[0084] In the first embodiment described above, the found VAS value is reflected in the NT update value, then the NT found value is updated based on this NT update value, and then the NT target water temperature is updated on the basis of this NT found value, however, the reflection method the found value of the VAS at NT target water temperature is not limited to this. For example, it can be arranged so that the found value of the COURT is reflected directly on the NT found value without using the NT value of the update. In addition, it can be arranged so that the found value of the SSS is reflected directly on the NT target water temperature without using the NT found value.

[0085] In the first embodiment described above, NT correction of the target water temperature is allowed only when the number of updates of the found value of the ACS reaches a predetermined value or more, however, this condition is not defining in the invention. That is, this can be done so that the NT correction of the target water temperature based on the found value of the ACS is carried out from the initial stage, in which the obtaining of the found value of the ACS begins.

[0086] In the first embodiment described above, the HT system 30 includes a three-way valve 42, which can electrically change state, but the invention is not limited to this. The three-way valve 42 in the first embodiment can be replaced by a thermostat (T / C), similar to that used in the BT system 16.

[0087] In the first embodiment described above, the NT target water temperature is updated within 3 seconds (the program shown in FIG. 4 is executed within 3 seconds), taking into account the delay that the NT water temperature becomes NT the target water temperature However, the update method is not limited to this. For example, this can be done so that the program shown in FIG. 4, was carried out in a period equal to the update period of the found value of the COURT, and so that the average target water temperature for a given time (about 3 seconds) of the resulting water was supplied to the NT system 30 as a “control value” according to claim 1

[0088] In the first embodiment described above, updating the NT of the found value is allowed without setting upper and lower limits (see step 110). The method of updating NT of the found value is not limited to this. It can be configured so that the upper and lower limits are provided for the magnitude of the change allowed for the NT of the found value within a given time or at a given distance of movement. In addition, it can be configured so that this type of upper and lower limits is set for the NT of the target water temperature without restrictions on the magnitude of the change in the NT of the found value or in addition to setting limits for the magnitude of the change in the NT of the found value. By setting such limits, it is possible to prevent the NT from improperly changing the target water temperature in the low temperature direction or in the high temperature direction.

[0089] In the first embodiment described above, the “cooling command issuing system” according to claim 1 is implemented by executing the program shown in FIG. 4 using the ECU 44. In addition, the temperature of the cooling water of the NT system 30 corresponds to the “cooling parameter" in paragraph 1 of the claims, NT the target water temperature corresponds to the "target value" and "control value" in paragraph 1 of the claims, and NT system 30 corresponds to the "cooling system" in paragraph 1 of the claims. In addition, the cooling water of the NT system 30 corresponds to the “cooling medium” in paragraph 6 of the claims, the BT system 16 corresponds to the “first cooling system” in paragraph 8 of the claims, and the NT system 30 corresponds to the “second cooling system” in paragraph 8 claims

[0090] Next, a second embodiment of the invention will be described with reference to FIG. 6 and 7. The system of this embodiment may be implemented using an ECU 44 executing the program described below in FIG. 7, instead of the program shown in FIG. 4 in the configuration of the first embodiment.

[0091] FIG. 6 is a diagram for explaining a method for implementing an ACS in this embodiment. As shown in FIG. 6, in this embodiment, the working area of the internal combustion engine 10 is divided into a plurality of areas, and the determined SAC value is set for a particular working area. In the internal combustion engine 10, the tendency for knocking to occur is not the same for all work areas. If the found CAS value is found for a particular work area, as shown in FIG. 6, then each found value of the COURT, properly indicating the tendency of detonation, can be prepared for all work areas.

[0092] FIG. 7 is a block diagram of a program executed by the ECU 44 in this embodiment. In this embodiment, the ECU 44 stores a computer program for executing the procedure shown in FIG. 7, and includes hardware such as an interface, a storage device, and a CPU for providing such an implementation.

[0093] The program shown in FIG. 7 is identical to the program shown in FIG. 4, except that steps 120-126 are interposed between steps 104 and 106. In this embodiment, the processes associated with determining the found ACS value for each work area are performed in steps 120-126. The program shown in FIG. 7 will be described focusing on a portion unique to this embodiment only.

[0094] The program shown in FIG. 7 is executed at a predetermined time of about 3 seconds, similar to the program shown in FIG. 4. In this program, following the determination in steps 100-104, the working area of the internal combustion engine 10 is read (step 120). More specifically, based on the engine revolutions NE and the accelerator opening degree Acc, it is determined to which of the work areas are divided, as shown in FIG. 6, refers to the current work area.

[0095] Next, the process of reading the found value of the ACS is performed (step 122). As described above, in the system of this embodiment, the found SAC value is determined for each work area shown in FIG. 6. At step 122, the found value of the COURT determined for the current work area is read.

[0096] Next, the NT map of the update values is read (step 124). In this embodiment, the ECU 44 stores the map shown in step 108 for each work area. The map is experimentally determined for each work area, which is usually suitable for calculating the NT value of the update based on the found value of the COURT. At step 124, a card corresponding to the work area is read from among these cards.

[0097] Next, the last value of the NT determination is read (step 126). In this embodiment, the ECU 44 stores the NT found value for each work area (this division of the work areas may be the same or different from the division of the work areas for the found value of the ACS). At step 126, the NT reads the found value determined last time for the current work area.

[0098] Next, using the found value of the COURT, the NT map of the update value and the last NT of the found value, read through the processes of steps 122-126, the processes of step 106 and subsequent steps are performed. By means of these processes described above, it is possible to establish the found value of the SSS correspondingly corresponding to the tendency of detonation in the current work area, as well as the NT target water temperature, corresponding to this tendency of the occurrence of detonation. Therefore, according to the system of this embodiment, the output and fuel consumption characteristics of the internal combustion engine 10 can be further improved compared to the case of the first embodiment.

[0099] All of the above modifications of the first embodiment can be used as modifications of the second embodiment.

[0100] In the second embodiment described above, the “cooling command issuing system” in claim 1 is implemented by executing the program shown in FIG. 7 using ECU 44. In addition, the NT map of update values shown in step 108 corresponds to the “update rule” in claim 5.

[0101] Next, a third embodiment of the invention will be described with reference to FIG. 8. The system of this embodiment may be implemented using an ECU 44 executing the program shown in FIG. 8, instead of the program shown in FIG. 4 in the configuration of the first embodiment.

[0102] In the first embodiment described above, the correction object based on the found value of the COURT (ie, the "control value" in claim 1) is the target water temperature. On the other hand, the system of this embodiment has the feature that the correction signal based on the NT value of the target water temperature is the mode signal for E-B / H 32, which is set based on the NT target water temperature.

[0103] That is, when feedback control is performed so that the NT of the water temperature reaches the NT of the target water temperature, the cooling ability of the NT of system 30 can be changed by changing the NT of the target water temperature. However, even if there is no NT change in the target water temperature, the cooling ability of the NT system 30 can be changed by increasing or decreasing the mode signal, which is set based on the NT target water temperature.

[0104] FIG. 8 is a flowchart for obtaining the same effect as in the case of the first embodiment, by reflecting the found value of the ACS on a mode signal set based on the NT of the target water temperature. This program is the same as the program shown in FIG. 4, except that steps 108-112 are replaced by steps 130-134.

[0105] The program shown in FIG. 8 is executed for a predetermined time of about 3 seconds, similar to the program shown in FIG. 4. In this program, after making the determinations in steps 100-106, the mode update amount is calculated based on the found COURT value (step 130). In this embodiment, the ECU 44 saves a map for converting the found ACS value to a mode update value, as shown in step 130. This card is set so that when the found ACS value increases, the mode update value acquires a larger value.

[0106] After performing the process described above, the found mode value is updated according to the following formula (step 132).

(Found mode value) = (last value) + (current update value) ... (formula 3), in which

“Last value” is the mode signal value calculated in the last program, and “current update value” is the mode update value calculated in step 130 in the current program. According to the process described above, when the found value of the ACS increases, the found value of the mode is substantially updated in the direction of increase.

[0107] After updating the found mode value, then, using the updated found mode value, the mode signal for the NT system 30 is calculated according to the following formula (step 134).

(Mode signal) = (NT basic mode) + (found mode value) ... (formula 4), in which

“NT basic mode” is the operating mode calculated by ECU 44 and supplied to E-V / N 32 for realizing NT of the target water temperature (not adjusted for the found value of the ECM).

[0108] As described above, the found value of the mode is substantially updated in the direction of increase when the found value of the ACS increases. Therefore, according to formula 4, the mode signal for E-B / H 32 tends to update to a larger value with respect to the NT base mode in a state where the occurrence of detonation is more likely. When the mode signal acquires a larger value, the discharge flow rate from the E-B / H 32 increases, and, accordingly, the cooling capacity of the NT system 30 increases. As a result, according to the processes described above, when the found value of the COD increases, the NT temperature of the water decreases to a lower temperature compared to the usual NT target water temperature so that the temperature operating parameters in relation to detonation can be improved. Therefore, according to the system of this embodiment, as in the case of the first embodiment, the occurrence of detonation can be effectively prevented by both delaying the ignition angle and the temperature of the NT system 30.

[0109] In the third embodiment described above, the correction object based on the found ACS value is limited to the mode signal, however, the object itself is not limited to this. That is, the cooling capacity of the HT system 30 can also be increased by using the state of the three-way valve 42 or the state of the fan of the HT radiator 36. Therefore, a correction based on the found ACS value can be applied to the degree of opening of the three-way valve 42 or the drive signal of the radiator fan.

[0110] All of the above modifications of the first embodiment can be used as modifications of the third embodiment. The method of the second embodiment, which calculates the found value of the ACS in each work area and calculates the “control value” in each work area, can be combined with a method that applies a correction based on the found value of the ACS to the mode signal.

[0111] In the third embodiment described above, the “cooling command issuing system” in claim 1 is implemented using the ECU 44 by executing the program shown in FIG. 8. In addition, the discharge flow rate from E-B / H 32 corresponds to the “cooling parameter" in paragraph 1 of the claims, and the mode signal for E-B / H 32 corresponds to the "target value" and "control value" in paragraph 1 claims In addition, the cooling water of the NT system 30 corresponds to the "cooling medium" in paragraph 7 of the claims.

[0112] Next, a fourth embodiment of the invention will be described with reference to FIG. 9 and 10. The system of this embodiment may be implemented using an ECU 44 executing the program described below and shown in FIG. 10, in addition to the program shown in FIG. 4, FIG. 7, or FIG. 8 in the configuration of the first embodiment.

[0113] In the internal combustion engine 10 shown in each of the first to third embodiments, there are cases where the NT system 30 reaches a cooling limit due to hardware conditions or conditions related to stable fuel consumption.

[0114] For example, the NT system 30 reaches the “hardware cooling limit” when all of the following conditions are met. (1) E-B / H 32 is driven by a 100% mode signal. (2) The three-way valve 42 is in a state in which all cooling water circulates through the NT radiator 36. (3) The NT fan of the radiator 36 rotates at an upper top speed.

[0115] In addition, in the internal combustion engine 10, there are cases in which if the periphery of the inlet openings has an excessively low temperature, premature ignition occurs. Therefore, when the NT temperature of the water drops to a temperature that can cause premature ignition, the NT system 30 reaches the “cooling limit with stable combustion”.

[0116] In the first to third embodiments, by controlling the BT system 16 independently of the HT system 30, the temperature operating parameters related to detonation can be improved without increasing mechanical loss on the internal combustion engine 10. However, in such a system, when the NT system 30 reaches the cooling limit and the occurrence of detonation is still not prevented, a situation may arise in which there is no alternative to excessive delay in the ignition angle to prevent the occurrence of detonation.

[0117] In FIG. Figure 9 shows the relationship between the magnitude of the factors that affect the fuel consumption characteristics of the internal combustion engine 10, for example, mechanical friction and cooling losses (ordinate axis), and VT water temperature. The internal combustion engine 10 shows the best fuel economy when the above factors are reduced. Factors such as mechanical friction and cooling losses are reduced when the heating of the internal combustion engine 10 increases. Therefore, as shown in FIG. 9, the fuel consumption of the internal combustion engine 10 becomes better when the VT water temperature increases.

[0118] (b) ° C shown in FIG. 9 is the temperature at which the rate of decrease of factors affecting fuel consumption essentially stops even with a further increase in the water temperature. In other words, this is the temperature at which the rate of decrease in factors with respect to the increase in the VT of the water temperature stops at a certain set value. The usual target temperature BT water temperature (set temperature T / C 28) is 85 ° C-90 ° C. (b) ° C is below this value and is about 80 ° C.

[0119] According to the characteristics shown in FIG. 9, it is seen that the fuel consumption characteristics of the internal combustion engine 10 are not so significantly affected by the increase in the WT of the water temperature in the region which is higher than (b) ° C. On the other hand, in the region where the water temperature is above 80 ° C, the amount of heat transferred from the cylinder block 12 to the cylinder head 14 also affects the peripheral temperature of the inlets. Therefore, in the context of improving the temperature operating parameters affecting detonation, it is preferable to reduce the temperature of the water temperature in addition to the cooling performed by the NT system 30.

[0120] Therefore, in this embodiment, in the case where the NT system 30 has reached the cooling limit, however, the occurrence of detonation is still not prevented, the VT water temperature is adjusted toward a temperature that is lower than the normal target temperature in the range of at least (b) ° C .

[0121] (a) ° C shown in FIG. 9 is the temperature that is used to determine in step 102 in the first through third embodiments. As described above, the region in which the VT water temperature is not higher than (a) ° C is the region in which detonation does not occur in the internal combustion engine 10.

[0122] In this embodiment, the ECU 44 executes the program shown in FIG. 4, FIG. 7, or FIG. 8, in order to control NT temperature of the water. In addition to this, in this embodiment, the ECU 44 executes the program shown in FIG. 10, in order to control the WT temperature of the water. The program shown in FIG. 10 is executed at a predetermined time of about 3 seconds, similar to the program shown in FIG. 4 etc. Among the steps shown in FIG. 10, those steps in which the same processes are performed as in the steps shown in FIG. 4, or the like, are denoted by identical reference numbers, respectively, a second explanation thereof is omitted.

[0123] In the program shown in FIG. 10, after determining the health of the system in step 100, it is determined whether or not the NT system has reached the cooling limit 30 (step 140). In this case, more specifically, the following definition is made.

- Whether or not the NT system has reached the “hardware cooling limit” 30 described above.

- Whether or not the NT system has reached the “cooling limit with stable combustion” 30 described above.

[0124] If it is determined during the process described above that the NT system 30 has not reached any of the cooling limits, it can be determined that there are reserves to improve the temperature operating parameters with the NT system 30. In this case, the current program ends immediately. On the other hand, if it is determined that the NT system 30 has reached any of the cooling limits, then it is determined whether the water temperature is higher or not than (b) ° C (step 142).

[0125] If at step 142 it is determined that the condition

VT Water temperature> (b) ° C

if it is not fulfilled, it can be determined that with a decrease in the VT of the water temperature, the fuel consumption characteristics of the internal combustion engine 10 are significantly reduced. In this case, the water temperature does not decrease, and the current program ends.

[0126] On the other hand, if the condition

VT Water temperature> (b) ° C

If it is performed, it can be determined that it is preferable to additionally use a decrease in the BT water temperature as a way to prevent detonation. Therefore, if the determination at 142 is affirmative, then the processes are performed to reduce the WT of the target water temperature through the determinations at steps 104 and 106.

[0127] In this embodiment, as in the case of the NT target water temperature, the VT target water temperature also decreases according to the tendency for detonation to occur. More specifically, the ECU 44 corrects the VT for the target water temperature based on the determined SAC value (steps 144-148). The processes in steps 144-148 are the same as the processes in steps 108-112 described above, except that “NT” is replaced with “BT”. However, the “VT reference value” in step 148 is the usual target temperature of the VT system 16.

[0128] According to the processes described above, when the found value of the COURT increases, ie when the internal combustion engine 10 is in a state where knocking is more likely, the BT target water temperature tends to update to a lower temperature with respect to the VT base value. The VT system 16 causes the VT water temperature to reach the VT water target temperature. Therefore, according to the processes described above, in a state where the occurrence of detonation is more likely, the VT water temperature becomes lower temperature, while the temperature operating parameters of the internal combustion engine 10 change in the direction in which detonation is difficult to occur.

[0129] FIG. 11 is a timing chart for explaining one example of the operation of the internal combustion engine 10, which is implemented by periodically executing the program described above. In FIG. 11, since the waveforms shown in the “Detonation” graph in the very top row, the “Ignition angle” graph in the second row, the “Found ECM value” graph in the third row, and the “NT target water temperature” graph in the fourth row are the same as those in the timing diagram shown in FIG. 5, then their repeated explanations will be omitted.

[0130] In the lowest row in FIG. 11 shows a graph of “BT target water temperature”. This graph more specifically shows BT the target water temperature 62 (solid line) and BT the water temperature 64 (dashed line). In the example shown in FIG. 11, the BT water temperature 64 exceeds the first threshold value (a) ° C in the process from time t4 to time t5. As a result, at time t5, the process of reflection of the found value of the SSS on the NT to the target water temperature begins.

[0131] In FIG. 11, the BT water temperature 64 exceeds the second threshold value (b) ° C in the process from time t5 to time t6. Further, at time t6, NT, the target water temperature undergoes a second correction in the low-temperature direction in response to the occurrence of detonation. It is assumed that the NT system 30 has reached the cooling limit in the second correction. That is, in the example shown in FIG. 11, it is assumed that at time t6 the following conditions are met: NT system 30 has reached the cooling limit, and VT water temperature is higher than (b) ° C.

[0132] Therefore, in the example shown in FIG. 11, after the time point t6, the WT, the target water temperature decreases, and after it the WT temperature of the water decreases. In this embodiment, the BT target water temperature may decrease until the BT water temperature decreases to (b) ° C. In the timing diagram shown in FIG. 11, an operation is illustrated in which correction to reduce the BT of the target water temperature is maximized, and as a result, the BT water temperature is reduced to (b) ° C.

[0133] After the time t7, if it is determined that the occurrence of detonation does not occur continuously, the ignition angle is moved forward to the base value 54, and the found COUR value is gradually updated to a lower value. As a result, both the NT target water temperature and the HT target water temperature 62 increase to the usual set temperatures after time t7.

[0134] As described above, when the NT system 30 reaches the cooling limit, the internal combustion engine 10 of this embodiment can further improve the temperature operating parameters by decreasing the VT temperature of the water. Therefore, according to the system of this embodiment, it is possible to further reduce the ignition angle delay as compared with the case of the first to third embodiments and to further improve the fuel consumption characteristics of the internal combustion engine 10 compared to the case of the first to third embodiments.

[0135] In the fourth embodiment of BT described above, the target water temperature decreases only when the BT water temperature is higher than (b) ° C, however, this condition is not fundamental to the invention. It can be done so that when a decrease in the water temperature BT is more preferable than a delay in the ignition angle, the target water temperature decreases when the water temperature is lower than (b) ° C.

[0136] In the fourth embodiment of BT described above, the target water temperature is reduced based on the found COD value, however, the invention is not limited to this. That is, it can be performed so that the target water temperature decreases, for example, by a fixed value, regardless of the found value of the COD.

[0137] In the fourth embodiment described above, the found COUR value is reflected in the BT update value, then the BT found value is updated based on the BT update value, and then the BT target water temperature is updated based on this BT found value. However, the method of reflecting the found value of the SSS at the target water temperature is not limited to this. For example, it can be configured so that the found value of the COURT will be reflected directly on the BT found value without using the BT update value. In addition, it can be configured so that the found value of the SAS will be reflected directly on the VT target water temperature without using the VT found value.

[0138] In the fourth embodiment described above, the correction of VT of the target water temperature is allowed only when the number of updates of the found value of the ACS has reached a predetermined value or more, however, this condition is not essential in the invention. That is, this can be done so that the VT correction of the target water temperature based on the found value of the ACS is carried out from the initial stage, in which the determination of the found value of the ACS begins.

[0139] In the fourth embodiment described above, the program shown in FIG. 10 is performed for a predetermined time of approximately 3 seconds, however, the updating method is not limited to this. For example, it may be configured such that the program shown in FIG. 10, will be performed in a period equal to the update period of the found value of the ACS, and that the average value of the target temperature of the water obtained as a result for a given time (about 3 seconds) is supplied as the target temperature to the BT system 16.

[0140] In the fourth embodiment described above, updating BT of the found value is allowed without setting upper and lower limits (see step 146). The method of updating BT of the found value is not limited to this. It can be configured so that the upper and lower limits will be set for the amount of change allowed for the VT of the found value for a given time or at a given distance. In addition, it can be configured so that this type of upper and lower limits is reflected in the target water temperature at the BT without reflecting the found value in the BT change value or in addition to reflecting the found value in the BT change value. By setting such limits, it is possible to prevent the VT from improperly changing the target water temperature in the low temperature direction or in the high temperature direction.

[0141] In the fourth embodiment described above, BT, the target water temperature corresponds to the “target temperature” according to claim 9. In addition, the second threshold value (b) ° C corresponds to a “determined temperature” in claim 10 of the claims.

Claims (32)

1. A control device for an internal combustion engine, comprising: a knock control system configured to calculate an ignition angle correction amount according to the presence or absence of detonation in an internal combustion engine so that the ignition angle correction amount is updated in the increasing direction when knocking occurs and is updated in the decreasing direction when knocking does not occur, while the knock control system is configured to calculate the ignition angle based on the magnitude of the ignition angle correction, and the detonation control system atsiey configured to spark ignition internal combustion engine with ignition angle obtained by delaying the ignition angle in response to the occurrence of knocking; a cooling system configured to cool an internal combustion engine; and an electronic control unit configured to supply a control value corresponding to the target value of the cooling parameter to the cooling system, the cooling system cooling the internal combustion engine in accordance with the control value, the electronic control unit being configured to adjust the control value based on the correction amount the ignition angle so that when the magnitude of the correction of the ignition angle increases, the magnitude of the correction I correction control value correction amount increases in the direction in which the cooling capacity of the cooling system is increased, wherein the cooling system of the internal combustion engine includes a first cooling system that mainly cools the cylinder block of the internal combustion engine, and a second cooling system that mainly cools the periphery of the inlet compared to the first cooling system, the first cooling system and the second cooling system respectively include flow channels of the cooling medium, independent of each other, and the electronic control unit is configured to supply a control value to the second cooling system. 2. The control device for an internal combustion engine according to claim 1, in which the electronic control unit is configured so as not to adjust the control value when the number of updates to the ignition angle correction amount according to the presence or absence of detonation is less than a predetermined value, and configured to adjust the control value when the number of updates to the ignition angle correction amount is a predetermined value or more. 3. The control device for an internal combustion engine according to claim 1, in which the electronic control unit is configured to update the found value of the cooling parameter based on the correction value of the ignition angle so that when the correction value of the ignition angle increases, the update amount to update the found value of the cooling parameter increases in magnitude of the update in the direction in which the cooling capacity of the cooling system increases while the electronic control unit is configured to determine the target value based on baseline parameter value found for cooling and the cooling parameter. 4. The control device for an internal combustion engine according to claim 3, in which the electronic control unit is configured to calculate the update value of the found value of the cooling parameter based on the correction value of the ignition angle and update the found value of the cooling parameter using the update value so that when the correction value of the ignition angle increases, the update value increases in magnitude of the update in the direction wherein the cooling capacity of the cooling system is increased. 5. The control device for an internal combustion engine according to claim 3 or 4, in which the knock control system is configured to calculate an ignition angle correction amount for each of the plurality of working areas of the internal combustion engine, and the electronic control unit is configured to save the update rule for each of the work areas to update the found cooling parameter value for each of the work areas based on the ignition angle correction value for each of the work areas, while the electronic control unit is configured to update the found cooling parameter value in each separate workspace according to the update rule for each of the workspaces. 6. The control device for an internal combustion engine according to claim 1, in which the cooling parameter is the temperature of the cooling medium, and the electronic control unit is configured to supply the target temperature of the cooling medium to the cooling system as a control value such that when the correction amount of the ignition angle increases, the correction value of the target value of the temperature of the cooling medium increases in the low temperature direction, and the cooling system is configured to control the cooling medium of the cooling system so as to realize the target value of the temperature of the cooling medium. 7. The control device for an internal combustion engine according to claim 1, in which the cooling system includes an electric water pump capable of changing the pumped flow rate of the cooling medium, the cooling parameter is the discharge flow rate of the electric water pump, and the electronic control unit is configured to supply a target value of the discharge flow rate to the cooling system as a control value such that when the correction amount of the ignition angle increases, the correction amount of the target value of the discharge flow increases in the direction of increasing the value. 8. The control device for an internal combustion engine according to claim 1, in which the electronic control unit is configured to transmit the target temperature to the first cooling system, the first cooling system is configured to control the cooling medium of the first cooling system so as to realize the target temperature of the first cooling system, and the electronic control unit is configured to reduce the target temperature for the first cooling system when the second cooling system has reached the cooling limit. 9. The control device for an internal combustion engine according to claim 8, in which the electronic control unit is configured to allow decreasing the target temperature for the first cooling system only when the temperature of the cooling medium of the first cooling system is above a certain temperature. 10. The control device for an internal combustion engine according to claim 8 or 9, in which the electronic control unit is configured to reduce the target temperature for the first cooling system based on the correction value of the ignition angle.

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